Proteins — practice question

Which levels of protein structure are always involved in the formation of an enzyme’s active site?

• Aprimary ✓, tertiary ✓, quaternary ✓
• Bprimary ✓, tertiary ✓, quaternary ✗
• Cprimary ✗, tertiary ✓, quaternary ✓
• Dprimary ✗, tertiary ✗, quaternary ✓